Regenerating a titanium silicalite catalyst

1. A process for regenerating a titanium silicalite catalyst fouled during a reaction between an olefin and a peroxide compound to produce an oxirane, the process comprising contacting the fouled titanium silicalite catalyst with a regeneration solution including at least one oxidizing agent to provide a regenerated titanium silicalite catalyst, wherein the regeneration solution has a pH of less than 2 and an oxidizing agent concentration of less than 0.50 weight percent based on a total weight of the regeneration solution prior to contact with the fouled titanium silicalite catalyst, exclusive of the titanium silicalite catalyst.

2. The process of claim 1 , further including adjusting the pH of the regeneration solution to less than 2 prior to contacting the fouled titanium silicalite catalyst with the regeneration solution.

3. The process of claim 1 , further including washing the regenerated titanium silicalite catalyst with an organic compound.

4. The process of claim 1 , wherein the regeneration solution has an oxidizing agent concentration in a range of from 0.10 weight percent to 0.49 weight percent, based on the total weight of the regeneration solution, exclusive of the titanium silicalite catalyst.

5. A process for regenerating a titanium silicalite catalyst fouled during a reaction between an olefin and a peroxide compound to produce an oxirane, the process comprising the step of contacting the fouled titanium silicalite catalyst with a regeneration solution having a pH of less than 2 and comprising at least one oxidizing agent and further comprising an organic compound to provide the regenerated titanium silicalite catalyst, with the proviso that the process does not comprise a washing step in addition to the contacting step.

6. The process of claim 5 , wherein the at least one oxidizing agent concentration is in a range of from 0.1 wt % to 50 wt % based on the total weight of the regeneration solution prior to contact with the fouled titanium silicalite catalyst, exclusive of the titanium silicalite catalyst.

7. The process of claim 5 , wherein the regeneration solution comprises the organic compound in a range of from 1 to 95 weight percent based on the total weight of the regeneration solution.

8. The process of claim 5 , wherein the organic compound is an aliphatic, cyclic, aromatic, halogenated, supercritical, or alcoholic organic diluent.

9. The process of claim 8 , wherein the organic compound comprises methanol.

10. The process of claim 5 , wherein the regeneration solution further comprises an effluent from the reaction between the olefin and the peroxide compound.

11. The process of claim 5 , wherein the at least one oxidizing agent is selected from the group hydrogen peroxide, ozone, organic peroxide compounds, inorganic peroxide compounds, and combinations thereof.

12. The process of claim 5 , wherein the peroxide compound is hydrogen peroxide, wherein the oxirane is epichlorohydrin and wherein the olefin is allyl chloride.

13. A regenerated titanium silicalite catalyst obtainable by the process as claimed in claim 1 .

14. The process of claim 3 , wherein the organic compound is an aliphatic, cyclic, aromatic, halogenated, supercritical, or alcoholic organic diluent.

15. The process of claim 13 , wherein the organic compound comprises methanol.

16. The process of claim 1 , wherein the regeneration solution further comprises an effluent from the reaction between the olefin and the peroxide compound.

17. The process of claim 1 , wherein regenerating the titanium silicalite catalyst is carried out at a temperature in the range of 0 degrees Celsius to 100 degrees Celsius.

18. The process of claim 1 , wherein the at least one oxidizing agent is selected from the group hydrogen peroxide, ozone, organic peroxide compounds, inorganic peroxide compounds, and combinations thereof.

19. The process of claim 1 , wherein the peroxide compound is hydrogen peroxide, wherein the oxirane is epichlorohydrin and wherein the olefin is allyl chloride.